The present invention relates to laser enhanced transluminal angioplasty catheters and particularly to apparatus in such catheters for controllng the insertion of an optical fiber or guide wire into the catheter, and for facilitating the introduction of fluids into the catheter.
Angioplasty catheter devices have been found useful in treating occlusions formed in blood vessels, for example from plaque build-up. In a laser enhanced catheter, an optical fiber is used to transmit a beam of laser energy from a generator to the fiber distal end, where the laser energy is delivered to and against the obstruction. Also, medication is delivered to the treatment area through one or more lumens in the catheter. Under controlled medication and exposure to the laser energy, the obstruction is partially removed, reduced in size, or eliminated entirely, effectively re-opening the blood vessel to restore normal circulation.
One known device for this technique is constructed by joining the proximal end of the catheter to a catheter manifold comprised of a plurality of luers. Such a catheter assembly is described in U.S. Pat. No. 4,669,465 (Moore et al), assigned to the assignee of the present application. The forward or distal luer is used to control inflation of a balloon at the catheter tip, while treatment fluids can be supplied to the catheter lumen through the remaining, proximal luers. The use of two or more proximal luers enables simultaneous introduction of a plurality of treatment fluids, and in controlled proportions.
Typically, the catheter is inserted into a blood vessel requiring treatment by use of a guide wire loaded into the manifold by a guide wire insertion tube, then extended distally of the tube, through the manifold and into the catheter. The insertion tube prevents the guide wire from mistakenly entering one of the luers rather than the catheter lumen, and is withdrawn along with the guide wire once catheter insertion is complete.
The central passage through the catheter manifold must be large enough to accept the guide wire tube, and to allow fluids from the proximal luers to flow around the tube. At the same time, the diameter of the passage, at some point before the distal luer, must be reduced to the approximate size of the catheter lumen. This can hinder retrograde passage (withdrawal) of the guide wire, as the guide wire tube can drift out of its concentric relation within the central passage and become caught against the distal tip of the insertion tube. In some cases, this movement completely prevents removal of the guide wire from the catheter manifold, rendering the catheter assembly inoperative. Similar difficulties are encountered in a laser enhanced transluminal catheter when attempting to insert the optical fiber in the catheter and manifold.
It therefore is an object of the present invention to provide a means for capturing the distal end of a filament insertion tube when loaded into a catheter manifold, and further guiding it into a coaxial relation with the manifold central passage.
Another object of the invention is to provide a means for positively maintaining a filament insertion tube coaxial with the central passageway so long as it remains loaded in the catheter manifold.
Another object of the invention is to maintain a guide wire introducer tube coaxial with a catheter lumen to facilitate the feeding of a catheter over the exposed end of a guide or exchange wire and into a blood vessel, and further to facilitate the withdrawal of the guide wire from the distal catheter lumen into the guide wire introducer and out of the manifold, all without inadvertently entering a luer or puncturing the hemostasis seal.
A further object of the invention is to allow fluid flow around a guide wire introducer when fully inserted.
Another object is to align an introducer for guide wire insertion through the seal and past the luers.
Another object is to align the filament insertion tube for fiber advance simultaneous with flow of fluids through the catheter.
Yet another object of the present invention is to guide and maintain a filament insertion tube in a coaxial relation within the central passage of a catheter manifold, while permitting flow of fluids through the passage and about the tube exterior.